Ratchet mechanism for calking guns



Dec, R9, 1950 s. CREWE 2,534,857

RATCHET MECHANISM FOR CALKING GUNS Filed Aug. 30, 1949 Eli INVENTOR,

SAMUEL CEEWE Z4 my ATTORNEYS Patented Dec. 19, 1950 UNITED STATES PATENT OFFICE RATCHET MECHANISM FOR CALKING GUNS Samuel Cree e, Cleveland, Ohio, assignor to firewe Manufacturing & Tool 00., Cleveland,

Application August 30, 1949., Serial No. 113,088

(!. fil -169) 3 Claims. 1

This invention relates to caulk guns and particularly to the ratchet mechanism in them which operates the piston and is an improvement over the devices shown in Patent No. 2,186,978 and No. 2,233,587 which vere granted to me on November 21, 1939, and March 4, 1941, respec tively.

The primary objects of the instant invention are substantially the same as those set forth in the aforesaid earlier patents; but in addition thereto this invention provides a mechanism having a toothless ratchet bar and automatic ratchet bar release which goes into operation when the manually operated parts are abnormal- 1y opened or rel .sed without requiring any extra manual operation or releasing manipulation.

Another object of this invention is to provide for the use of a toothless ratchet bar that can be moved entirely free of the driving mechanism once the bar is released whi e at the same time being instantly reengageable by the ratchet mechanism regardless of the position of the ratchet bar.

. These and other objects of the invention will. become apparent from a reading of the following specification and claims together with the accompanying drawing wherein like parts are referred to and indicated by like reference characters and wherein:

Figure l is a side elevation of a caulking gun, parts of which are broken away to show details of construction, which indicates the normal position of the ratchet mechanism parts;

Figure 2 is a cross-sectional view of the ratchet mechanism taken along the lines and in the direction of the arrows 2-4: of the Figure 1;

Figure 3 cross-sectional view of the same mechanism taken along the lines and in the direction of th arrows 3-3 of the Figure 1;

Figure 4 is a right end view of the pawl illustrated in Figure 1;

Figure 5 is a front view of the saline:

. Figure 6 is a right end View of the dog illustrated in the Figure 1;

Figure 7 is a front view of the same;

Figure 8 is a side view of the ratchet mechanism showing relative positions of the various elements when the ratchet bar has been moved forward from the position shown in the Figure 1 and is about to become stationary and ready for another projecting operation;

Figure 9 is a side view of the same mechanism showing the position of the parts when the ratchet is automatically disengaged from the pawl and dog members; and

Figure 1G is side view of the ratchet mechanism showing the relative positions of the various elements when the operating lever has been allowed to return to a normal open position ready for another projecting operation while the bar 2 is firmly held by the tilted dog against backward movement. I

Broadly this invention consists of a barrel l2, a nozzle 13 on the forward end of the barrel, and the ratchet mechanism on the rear end of the barrel. Both the barrel and the nozzle have been specifically described in my prior patents heretofore referred to in this specification.

The ratchet mechanism, as shown, consists of a handle member 28, an operating lever an, a smooth toothless ratchet bar 413 and pawl and dog members 58 and 56 respectively. Each of these members will be described in detail and in the order just mentioned.

The handle member .28 is rn'adeof sheet metal, formed hollow with side Walls 2! and 22 and a rear well 2.3. The lower portion of the side walls 2i and 22 are shaped to serve as a suitable grip element 24. The forward end of the handle member has attached thereto a cup 25 which forms a front wall for the handle member and has a conventional means for engaging the barrel I 2.

The upper portion of the rear wall 23 is provided with a round hole as which is aligned with the axis of the barrel l2 and through which the toothless ratchet bar it may move freely. The

center of the cup 25 is simultaneously provided with a hole 2! which permits the free passage of the bar ll) into and out of the barrel 12. An inwardly protruding boss or stop 28 is positioned on the rear wall 23 above the hole 26. This handle member is made smooth with rounded wall corners and without sharp edges or unnecessary projections extending therefrom.

The operating lever is also made of sheet -metal and is substantially U-shaped in crosssection. It is pivoted on the handle member by the pivot pin 3i, with the open side of the U faced toward the rear wall 23 of the handle member An elongated hole 35 is located in the closed the pivot pin 3!. The bar ll passes through the Lver hole 35. The width and length of the hole being such that it will clear the bar 40, and

the hereinafter described coil spring 53 which is mounted thereon, in all possible positions of the lever 30.

The lower arm of the lever, the portion below the 3! is shaped to form a reciprocating grip element 32, and opens or closes with respect to the grip element 2c of the handle 2s. A simple expansion spring 29 is supported between the two grip elements .25 and 32 so as to separate th m as far as possible. The separated position,

' as shown in the Figure l, is the normal position of the grip elements.

The ratchet bar it is simply a length of round rod threaded at one end to engage the piston eleit and having a simple cross bar 4| welded or otherwise affixed to the opposite end whichserves as a grip to facilitate the convenient manipulation of the bar. The ratchet bar 40 is perfectly smooth all around having no teeth or serrations along its entire length.

Reference character 50 indicates a pawl member made of metal or other suitable material, shaped as shown in the Figures 4 and 5. The upper half of the pawl 50 is bent at an obtuse angle to the lower half, as shown, and a hole 5| is located in the lower portion of the pawl just below the bend. The diameter of the hole 5| is slightly larger then that of the bar 4| so that the pawl may be tilted slightly from the perpendicular when the pawl is mounted on the bar 40. The pawl 50 is mounted on the bar 40 between the cup 25 and the operating lever 30 as shown in the Figures 1, 8, 9 and 10. A coil spring 52 is mounted on the bar 40 between the cup 25 and the pawl 50 and normally operates to urge the pawl 50 against the upper end of the lever 38.

A dog member 60 made of material similar to that of the pawl member 50 and shaped substantially as shown in the Figures 6 and '1 is mounted on the bar 40 between the lever 30 and the rear wall 23 of the handle 20 as shown in the Figures 1, 8, 9 and 10. The dog has a mounting hole 6| therethrough in its lower section and a shallow hole or seat 62 in its upper portion.

The hole 6| is slightly larger than the diameter of the rod 40 so that the dog may be tilted from the perpendicular relative the bar 4!]. A second coil spring 63 is mounted on the bar 4!! between the pawl 59 and the dog 60 and normally acts to tilt the dog from the perpendicular. A third coil spring 64 is seated in the hole 62 with its free end pressed against the rear wall 23 of the handle 20 to further aid the spring 53 in its efforts to tilt the dog 60 from the perpendicular.

To project the ratchet bar and piston forward the lever grip 32 is moved rearward against the pressure of the spring 29 to the position indicated by reference numeral 32d in the Figure 1. The relative positions of the various elements, when the lever grip 32 is moved rearward, is seen most clearly in the Figure 8. The upper end of the lever 20 presses against the curved upper end of the pawl 50 thereby causing the lower or straight portion of the pawl to tilt forward, which in turn, forces the leading edge of the pawl. hole 5| to dig into the ratchet bar and lock the pawl and bar together.

Further movement of the lever 30 carries the locked car and piston forward into the barrel to eject the contained caulk material through the nozzle |3-. At the same time, the dog member 68 is maintained in its tilted condition by the interaction of the two coil springs 63 and 64. The bar 40 is free to move forward through the dog hole El and the dog 60 may even move with it away from the stop 21 by a fraction of an inch as shown in the Figure 8.

Each rearward movement of the lever advances the bar 48 only a short distance so that the lever must be released and retracted repeatedly to advance the bar and piston through the barrel. When the lever is released gradually the expansion spring 29 moves the lever 30 forward. At the same time, the upper portion of the lever moves rearward as shown in the Figure 10.

The locked pawl and bar momentarily follow the lever rearward until the tilted dog member 60 touches the stop 28, at which instant, the edges of the dog hole 5| dig into the surface of the toothless bar M3 and lock it against further rearward movement. The further backward movement of the upper end of the lever permits the pawl 50 to straighten up and again become perpendicular to the bar 40 under the backward urging of the spring 52. The pawl is then free to follow the lever backward along the bar 40.

If the hand grip 32 of the lever 30 is pressed rearward before the upper end of the lever has touched the dog 56, as shown in the Figure 10, the cycle may be repeated as often as desired without releasing the pressure built up ahead of the piston in the barrel, and the piston may be advanced continuously. However, if the lever 30 is released quickly, or pushed abnormally forward, the upper end of the lever will strike the upper end of the dog 60, as shown in the Figure 9. The pressure of the lever against the face of the dog causes it to pivot on the stop 28 which acts as a fulcrum thereby causing the dog to straighten up and align itself squarely with the bar 40. The edges of the dog hole 6| will then be brought parallel to the face of the bar it and the bar will be free to move rearwardly of the dog 50 to release the pressure in the caulk gun barrel 12.

When the dog is in its released condition the bar 49 can be pushed in or out of the barrel l2 freely and easily by means of its handle 4 This feature makes it easy to reload the barrel with caulking compound since there are no teeth on the bar 43 to accidentally impede the smooth outward manual movement of the bar that is necessary drawing in a new supply of caulk.

The pressure and weight of the two springs 63 and 64 are so balanced that the dog 60 is always tilted unless the lever 30 is pressing against it to hold it straight.

The gun requires only one hand to both eject and instantly stop the flow of caulk. It should be noted that this ratchet mechanism is simple in structure and therefore not likely to get out of order at inopportune times.

There are no teeth on the ratchet bar to wear out or any complex shaped operating members pivotally associated with the ratchet bar. All the operating members are mounted directly on the smooth toothless bar 40 and consist of a pawl and dog having straight bored holes therethrough.

The action is smoother and more reliable than the prior art devices in that there are not any teeth on the bar 40 to wear or to limit the length of the power stroke or the point at which the power stroke shall begin. The power stroke can be as long or as short as desired within the mechanical limits of the device.

It will now be clear that there is provided a device which accomplishes the objectives heretofore set forth. While the invention has been disclosed in its preferred form; it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claims.

I claim:

1. A ratchet mechanism, comprising in combination, a hollow handle member; an operating lever pivotally mounted. in the hollow handle member; a toothless ratchet bar movable through the handle and operating lever; a rectangularly shaped pawl member slidably mounted on the said ratchet bar in front of said operating lever and. having an upper lever engaging portion and a lower ratchet bar engaging position, the said upper portion being bent at an obtuse angle to the lower portion and toward the operating lever, the lower portion having a ratchet bar engaging hole therethrough; first spring means normally holding said pawl member lower portion perpendicular to the longitudinal axis of th ratchet bar; a dog member slidably mounted on the ratchet bar to the rear of said operat ing lever, second spring means normally urging said dog member into a tilted position with reference to the longitudinal axis of the said ratchet bar, in which position the dog member is in wedged en agement with the said bar, and means on the handle member providing a stop to limit the movement of the dog member in one direction, the aforesaid operating lever being moveable between a firstposition wherein it is engaged with the pawl member to tilt it against the urging of the first spring means into wedged engagement with the ratchet bar, a second position wherein the pawl is free to resume its normal slidable condition on said ratchet bar, and a third position wherein the operating lever engages the dog member to pivot it against the stop thereby causing the dog member to assume a position perpendicular to the longitudinal axis of the ratchet bar, in which position the dog member is disengaged from the said ratchet bar.

2. A ratchet mechanism, comprising in combination, a hollow handle member; an operating lever pivotally mounted in the hollow handle member and having a hole therethrough above its pivot point and at a right angle thereto; a toothless ratchet member movable through the handle and operating lever hole; a rectangularly shaped pawl member slidably mounted on the said ratchet bar in front of said operating lever and having an upper lever engaging portion and a lower ratchet bar engaging portion, the said upper portion being bent at an obtuse angle to the lower portion and toward the operating lever, the lower portion having a ratchet bar engaging hole therethrough; a first coil spring mounted on the ratchet bar and normally holding said pawl member lower portion perpendicular to the longitudinal axis of the ratchet bar; a rectangularly shaped dog member slidably mounted on the ratchet bar to the rear of said operating lever and having upper and lower portions lying in the same plane, the said lower portion having a ratchet bar engaging hole therethrough, a second coil spring mounted on the ratchet bar and normally urging said dog member into a tilted position with reference to the longitudinal axis of the said ratchet bar, in which position the dog member is in wedged engagement with the said bar, and a stop mounted on the handle member and engageable with the dog member above the ratchet hole, the aforesaid operating lever being movable between a first position wherein it is engaged with the upper portion of the pawl member to tilt the lower portion forward into wedged engagement with the ratchet bar against the backward urging of the first coil spring, a second position wherein the pawl member is free to resume its normal slidable condition on the said ratchet bar, and a third position wherein the operating lever engages the upper portion of the dog member to pivot it against the stop thereby causing the dog member to take a position perpendicular to the longitudinal axis of the ratchet bar, in which position the dog member is disengaged from the said bar.

3. A ratchet mechanism, comprising in combination, a hollow handle member having front, rear and side walls; an operating lever pivotally mounted in the hollow handle member between the said side walls and having a hole therethrough above its pivot point and at right angle thereto; a toothless ratchet member movable through the handle member and operating lever hole; a rectangularly shaped pawl member slidably mounted on the said ratchet bar between the front wall of the hollow handle member and the operating lever and having an upper lever engaging portion and a lower ratchet bar engaging portion, the said upper portion being bent at an obtuse angle to the lower portion and toward the operating lever, the lower portion having a ratchet bar engaging hole therethrough; a first coil spring mounted on the ratchet bar between the front wall of the hollow handle member and the pawl and normally holding said pawl member lower portion perpendicular to the longitudinal axis of the ratchet bar, a rectangularly shaped dog member slidably mounted on the ratchet bar between the operating lever and the rear wall of the hollow handle member and having upper, medial and lower portions lying in the same plane, the said upper portion having a blind hole in the side toward the rear wall of the handle member, the lower portion having a ratchet bar engaging hole therethrough; a second coil spring mounted on the ratchet bar between the pawl member and the dog member, a third coil spring mounted in the said dog member blind hole and extending between the upper portion of the dog member and the rear wall of the said handle member, the second and third coil springs co-operating to normally urge said dog member into a tilted position with reference to the longitudinal axis of the said ratchet bar, in which position the dog member is in wedged engagement with the said bar; and an inwardly extending stop formed integral with the rear wall of the handle and engageable with the dog member in its medial portion, the aforesaid operating lever being movable between a first position wherein it is engaged with the upper portion of the pawl member to tilt the lower portion forward into wedged engagement with the ratchet bar, against the backward urging of the first coil spring, a second position wherein the pawl member is free to resume its normal slidable condition on the said ratchet bar, and a third position wherein the operating lever engages the upper portion of the dog member to pivot it against the stop thereby causing the dog member to take a position perpendicular to the longitudinal axis of the ratchet bar, in which position the dog member is disengaged from the said bar.

SAMUEL CREWE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,305,238 Coates Dec. 15, 1942 2,367,346 Good Jan. 16, 1945 

